I've been following the progress of this terraforming simulation for a few months now. It's in the late Beta stage, so the graphics are a good bit better than they look even in the intro videos on the games website.

The premise is that you are part of a three ship terraforming effort that is sent to Mars as a last ditch effort to create a livable space for humanity before we all go extinct on Earth. On the way to Mars your ships get shot down, and you crash land on the surface. The game is all first or third person, and you literally have to scavenge the smashed up parts of your spaceship to make tools to stay alive on the surface of mars. You build a shelter in the rock, pressurize it, heat it. You build machines to make light and heat, water and power. Then you plant some food and figure out what the heck happened.

Eventually you plant bacteria on the polar permafrost and surface dust that starts to thicken the atmosphere and warm up Mars. The warmer it gets, the more life you can introduce. At one point you have to dig towards the core and set off home made nuclear bombs to get the magnetosphere and the volcanos going to help deal with the deadly radiation. You create steel from dust, soil from irradiated waste, and a living world from a dead one. This sim is HARD, you have to work for every breath. At one point I was chasing the setting sun with my solar panels in hand, juggling my oxygen and water use, just barely creating enough food to survive, while the sky turned bluer and bluer over my head.

Eventually you can turn Mars into a forest, with a full ocean and clouds and rain.